This invention relates to a novel system to safely remove the bottom head of a coking drum under the most severe load conditions.
In the operation of delayed coking systems where coking of various hydrocarbon streams is carried out, the coke formed is deposited on the inner walls of the drum and is periodically removed. To remove the coke it is necessary to remove the bottom head unit by removing the bolts attaching it to a flange on the vertical coking drum and then attaching a chute to the bottom of the drum to direct the removed coke to a storage area or to a railroad car. This operation is hazardous for several reasons:
a) Cooling water which is introduced into the hot drums prior to the removal of the bottom head becomes extremely hot and could leak from the loosened head and scald workers in the area.
b) The load of undrained water and loose coke within the drum may exceed the limits of the support system and cause heavy equipment to fall on workers.
c) Positioning of the chute and necessary removal of flanges is done with workers at risk to the conditions of a and b.
The present invention provides a novel and safe system for deheading the coking drum without the hazards indicated above.